Kelly Cock Valve

Kelly cock valves close off the bore of the drill string, holding the mud column in the top drive or kelly when it is disconnected from the string. They control mud flow during normal drilling and are operated from the rig floor. A standard setup uses two valves: an upper and a lower kelly valve.

The valve is available in one-piece and two-piece designs with a full free passage for maximum circulation and minimal pressure loss. Valves are made to the latest API 7-1 or NS-1 specification, with API or proprietary connections, in standard or H2S-resistant versions, Class 1 construction.

Main features

• Simple construction for trouble-free operation and easy servicing
• Sealed lubrication packing
• 10,000 or 15,000 psi working pressure (test pressure 15,000 / 22,500 psi)
• Delivered with operating wrench and disassembly tool
• Seal kits and complete repair kits available as spare parts

Available series

Hydraulic testing

Each valve is hydraulically bench tested to API Spec 7-1 (latest edition) and delivered with its individual pressure test record, in two steps:

• Shell test: pressurized to test pressure for 3 minutes, depressurized, then pressurized again for at least 10 minutes
• Seat test: pressurized from the pin end to working pressure for at least 5 minutes

No visible leakage is permitted and the pressure drop must not exceed 1% of the test pressure.

Compatibility with drop-in check valves (RDCV)

When an RDCV is dropped into the string, its OD must pass through the free ID of the kelly valve: